QoS Policy question

[Steven Williams]

• Ok looking at this policy:  Beside all the voice protocols that I am defining in the first class map, I want the rest of the traffic no matter what it is to fall into the default class map. So does this work?

  class-map match-any MPLS_VOICE_CHILD

    match protocol rtp

    match protocol rtsp

    match protocol sip

    match protocol skinny

    match protocol h323

    match ip dscp ef !

  !

  policy-map MPLS_QUEUEING_CHILD

    class MPLS_VOICE_CHILD

      priority percent 25

      set ip dscp ef

    class class-default

  !

  !

  !

  policy-map MPLS_POLICYMAP_PARENT

    class class-default

      shape average 50000000

      set ip dscp default

      service-policy MPLS_QUEUEING_CHILD

  !

  !

  !

  !

  !

  interface FastEthernet0/0.3086

  description **

  bandwidth 50000

  encapsulation dot1Q 3086

  ip vrf forwarding mpls

  ip address x.x.x.x 255.255.255.252

  service-policy output MPLS_POLICYMAP_PARENT

  Will this allow all traffic that isnt marked for voice protocols to fall into the default class and be set as dscp 0? And will it use the rest of the 100 percent of the pipe (which is 74 percent) for that class of traffic (DSCP 0)?

[Joseph W. Doherty]

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Posting

"Will this allow all traffic that isnt marked for voice protocols to fall into the default class and be set as dscp 0"

Not as I suspect you intend.  See revision policy-maps, below:

policy-map MPLS_QUEUEING_CHILD

  class MPLS_VOICE_CHILD

    priority percent 25

    set ip dscp ef

  class class-default

    set ip dscp default

policy-map MPLS_POLICYMAP_PARENT

  class class-default

    shape average 50000000

    set ip dscp default

    service-policy MPLS_QUEUEING_CHILD

"And will it use the rest of the 100 percent of the pipe (which is 74 percent) for that class of traffic (DSCP 0)?"

Class-default, as configured in child, can use 100% of the parent's bandwidth.

BTW, on most platforms, your MPLS_VOICE_CHILD will only be limited to 25% if there's queuing.

[Steven Williams]

But I want to make sure there is always bandwidth for voice? Am I not queuing with the "Priority" command?

[Joseph W. Doherty]

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

Yes, your policy guarantees bandwidth for voice, in fact, 25%.  On some platforms, voice might even use more.

However, unused voice bandwidth is available to other traffic, up to 100% with your policy.

[Steven Williams]

So there is no way to say that even if voice isnt using 25% of the pipe, only allow all other traffic to use 74 percent regardless?

Also is there an "order of operation/processing" when it comes to the QoS policy? Is the class default evaluated last?

So if I was to put in a match any on the class default would the voice traffic get marked before the class default was looked at?

[Joseph W. Doherty]

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

"So there is no way to say that even if voice isnt using 25% of the pipe, only allow all other traffic to use 74 percent regardless?"

No, not saying that.  You might be able to police or shape class-default too.

"Also is there an "order of operation/processing" when it comes to the QoS policy? Is the class default evaluated last?"

Yes, top to bottom, with class-default always at bottom (regardless how you enter it).

"So if I was to put in a match any on the class default would the voice traffic get marked before the class default was looked at?"

Class-default is already an implicit match any (not otherwise matched).  Other classes, tht match traffic, will process that matched traffic.

[Steven Williams]

Ok so as long as I am setting other classes to match certain traffic, that said traffic will never hit class default. class default is like the clean up bucket. "Anything that every other class map doesn't match I will catch it and mark it as dscp 0.

So I am kind of looking at QoS policys like programming in a way...you define your variables (class maps), then you set them in the policy which is kind of like a sub routine. But I can see that it could very complex depending on how much you nest.

[Joseph W. Doherty]

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

Yep, class-default is like a "clean up", or, none of the above.

There's always a class-default.  If you don't explicitly define it, there will be one implicitly.